Use tabulated heats of formation to determine the standard heats of the following reactions in $k\frac{J}{m}ol,$ letting the stoichiometric coefficient of the first reactant in each reaction equal one.

a$.$ Nitrogen and oxygen reacts to form nitric oxide $($NO$)$

b$.$ Gaseous n$-$pentane and oxygen react to form carbon monoxide and liquid water.

c$.$ Liquid $n-$hexane and oxygen react to form carbon dioxide and water vapor.

d$.$ Liquid sodium sulfate and carbon monoxide react to form liquid sodium sulfate and carbon dioxide.